The invention described herein pertains to self-dimming headlights, and more particularly to a radiofrequency (RF) modulator in conjunction with a relay switch for dimming headlights. Almost everyone who drives at night has at one time or another experienced the discomfort of oncoming traffic forgetting to turn off their high beams. Not only can the bright lights cause discomfort, but they can be distracting and even dangerous when the road becomes difficult to see. Additionally, short of flashing their own lights there is little a person can do to warn someone that their high beams are on. While multiple attempts have been made to automatically dim headlights when oncoming traffic is detected, there is a failure to anticipate oncoming traffic in the art.
An early attempt at developing automatically dimming headlights is seen in U.S. Pat. No. 2,737,599 to Harold A. Goldsmith which describes a photosensitive device connected in series with a vehicle's headlights. When the lights from an oncoming vehicle shine on the photosensitive device the conductive properties of the circuit are affected, leading to a dimming of the lights. While the patent describes a method for automatically dimming headlights, it fails to anticipate vehicles without headlights shining directly on the photosensitive device. U.S. Pat. No. 2,959,709 to Charles H. Odom discloses an improved light sensitive device for automatically dimming headlights. The primary object of the '709 patent is to prevent dimming in response to objects on one side of the vehicle, such as illuminated store windows or street lights. This is accomplished through the use of a photosensitive device which detects the direction of light entering the sensor. Similar to the '599 patent, there is no anticipation of oncoming traffic prior to light shining on the photosensitive device.
Another attempt to effectively develop automatically dimming headlights can be seen in U.S. Pat. No. 7,613,327 to Joseph S. Stam et al. The apparatus disclosed in the '327 patent utilizes an ambient light sensor to determine the need for headlights along with an image sensor to determine whether vehicles are in close proximity. The use of an image sensor allows for automatic dimming when there are no oncoming headlights to trigger a photosensitive device. This is useful for situations where high beams are not desired, but there are no direct light sources to trigger dimming, such as when one car is following another. As with the previously mentioned patents, there is no anticipation of oncoming traffic, only an ability to dim the headlights when in close proximity to another vehicle or after oncoming traffic lights are already shining directly at the device.
Although the various devices observed may fulfill their individual, particular objectives, each device suffers from one (1) or more disadvantage or deficiency related to design or function. Whether taken singly, or in combination, none of the observed devices disclose the specific arrangement and construction of the instant invention.